Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already establish read-only and closed-world behavior, so the safety profile is covered. The description adds concrete value by naming the data surfaced (hours, tasting fee, booking requirement, features, contacts, booking link), telling the agent what it will get back. It does not address missing-ID behavior, keeping it short of a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single well-formed sentence with the return scope front-loaded after the verb. Every clause earns its place by naming a data category the agent will receive, with no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter read tool with annotations covering safety and no output schema, listing the returned fields is the right amount of context. The only material gap is id provenance/format and error handling for an unknown id.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the full burden for the single 'id' parameter. It only says 'by id' without stating the id's format, source (e.g., from search_wine_farms results), or whether it is a slug or numeric identifier, which is insufficient compensation for the coverage gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Returns full visitor details for one wine farm by id') and enumerates the returned content fields. This clearly distinguishes it from sibling search_wine_farms (listing) and plan_winelands_day (planning), which an agent can tell apart without opening schemas.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'by id' implies this is a lookup for a single already-known farm, which is useful context. However, it never explicitly says when to use this versus search_wine_farms or plan_winelands_day, nor does it mention any exclusions or prerequisites.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.